Optical lens and near-eye display device

Abstract

The present invention provides an optical lens and a near-eye display device, which sequentially include, from the human eye entrance pupil side to the image source side along the reverse direction of light transmission: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens; the first lens has a positive optical power, and the light-emitting surface of the first lens is a convex surface; the second lens has an optical power, and the light-emitting surface of the second lens is a convex surface; the third lens has a negative optical power, the light-emitting surface of the third lens is a concave surface, and the light-incident surface of the third lens is a concave surface; the fourth lens has a positive optical power, and the light-incident surface of the fourth lens is a convex surface; the fifth lens has a positive optical power; the distance CT W between the light-incident surface of the fifth lens and the image source on the optical axis is adjustable. The optical lens provided by the present invention has the advantages of adjustable diopter and excellent imaging quality.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging lenses, and in particular to an optical lens and a near-eye display device. Background Art

[0002] As an emerging information technology, virtual reality technology (VR) has developed rapidly in recent years and has been widely used in many fields, including entertainment, education, medical treatment, industrial manufacturing, etc., among which there is great potential for the correction of myopia. VR devices transmit and magnify the content of the display screen to the human eye through an optical system, thereby realizing the magnification of the displayed image and allowing users to experience immersive large-screen viewing. At present, VR head-mounted display devices used for myopia correction are developing in the direction of personalization, comfort, and high definition. At the same time, high definition, low distortion, and visual comfort have also become key evaluation indicators for the quality of VR head-mounted displays. Low distortion does not require distortion correction and high definition determines visual comfort. In addition, the larger the range of diopter adjustment, the larger its range of action. In order to meet these requirements, the optical system needs to simultaneously achieve low distortion, high imaging quality, and a wide range of diopter adjustment. Therefore, meeting the above optical properties at the same time brings great challenges to the design and aberration optimization of the optical system. Summary of the invention

[0003] In view of the above problems, the object of the present invention is to provide an optical lens having the advantages of adjustable diopter and excellent imaging quality.

[0004] The technical solution adopted by the present invention is:

[0005] An optical lens, composed of five lenses, including: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens in sequence from the entrance pupil side of a human eye to the image source side along the reverse direction of light transmission; the first lens, the second lens, the third lens, the fourth lens, and the fifth lens each include a light entrance surface close to the image source side and a light exit surface close to the entrance pupil side of the human eye;

[0006] The first lens has positive optical power, and the light-emitting surface of the first lens is a convex surface;

[0007] The second lens has optical power, and the light-emitting surface of the second lens is a convex surface;

[0008] The third lens has negative optical power, the light exiting surface of the third lens is a concave surface, and the light incident surface of the third lens is a concave surface;

[0009] The fourth lens has positive refractive power, and the light incident surface of the fourth lens is a convex surface;

[0010] The fifth lens has positive optical power;

[0011] The distance CT between the incident light surface of the fifth lens and the image source on the optical axis is adjustable. W The range is adjustable;

[0012] Among them, the distance TL on the optical axis from the light-emitting surface of the first lens to the incident light surface of the fifth lens and the effective focal length f of the optical lens satisfy: 0.9 < TL / f < 1.1;

[0013] The distance TL on the optical axis from the light-emitting surface of the first lens to the incident light surface of the fifth lens and the display area length IH of the image source that the optical lens can match satisfy: 1.9 < TL / IH < 2.2.

[0014] Further preferably, the display area length IH of the image source that the optical lens can match and the effective focal length f of the optical lens satisfy: 0.48 < IH / f < 0.5; the exit pupil distance ED of the optical lens and the effective focal length f of the optical lens satisfy: 0.29 < ED / f < 0.3.

[0015] Further preferably, the effective focal length f of the optical lens and the combined focal length f345 of the third lens, the fourth lens, and the fifth lens satisfy: 0.4 < f345 / f < 2.5.

[0016] Further preferably, the effective aperture DM11 of the light-emitting surface of the first lens and the effective aperture DM52 of the incident light surface of the fifth lens satisfy: 0.38 < DM11 / DM52 < 0.44; the maximum effective aperture DM1 of the first lens, the maximum effective aperture DM2 of the second lens, the maximum effective aperture DM3 of the third lens, the maximum effective aperture DM4 of the fourth lens, and the maximum effective aperture DM5 of the fifth lens satisfy: DM1 < DM2 < DM3 < DM4 < DM5.

[0017] Further preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.5 < f1 / f < 4.

[0018] Further preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -1.2 < f3 / f < -0.2; the effective focal length f of the optical lens and the radius of curvature R6 of the incident light surface of the third lens satisfy: 0.1 < R6 / f < 1.

[0019] Further preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.3 < f4 / f < 6.5; the effective focal length f of the optical lens and the radius of curvature R8 of the incident light surface of the fourth lens satisfy: -4 < R8 / f < -0.4.

[0020] Further preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.5 < f5 / f < 1.6.

[0021] Further preferably, the sum ∑CT of the central thicknesses of the first lens to the fifth lens along the optical axis respectively and the distance TL on the optical axis from the light-emitting surface of the first lens to the light-incident surface of the fifth lens satisfy: 0.5 < ∑CT / TL < 0.7.

[0022] Further preferably, the central thickness CT1 of the first lens and the air gap CT12 on the optical axis between the first lens and the second lens satisfy: 0.2 < CT1 / CT12 < 0.8; the central thickness CT2 of the second lens and the air gap CT12 on the optical axis between the first lens and the second lens satisfy: 0.35 < CT2 / CT12 < 0.6.

[0023] The present invention also provides a near-eye display device, which sequentially includes, along the optical signal transmission direction: an image source, the above optical lens; the image source is used for emitting an optical signal, and the optical signal includes image information; the optical lens is arranged in the light-emitting direction of the image source, and the fifth lens is arranged closer to the image source than the first lens, and the optical lens is used for modulating the optical signal emitted by the image source and transmitting it to the human eye.

[0024] Compared with the prior art, the optical lens provided by the present invention has a telephoto characteristic through a specific surface shape setting and a reasonable optical power distribution, can better present larger local details, improve the picture quality, and at the same time has a larger image plane, can match a larger-size image source (display screen) to achieve high-definition imaging, and brings an excellent sensory experience to users. By adjusting the spatial interval distance between the entire lens group and the image source on the optical axis, a diopter adjustment from -7D to +3D can be realized, and all have small distortion and high imaging quality, bringing an excellent sensory experience to users. Description of the Drawings

[0025] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0026] Figure 1 is a schematic structural diagram of the near-eye display device provided in the embodiment of the present invention.

[0027] Figure 2 is a schematic structural diagram of the optical lens provided in Embodiment 1 of the present invention.

[0028] Figure 3 is the field curvature curve diagram of the optical lens provided in Embodiment 1 of the present invention.

[0029] Figure 4 This is a F-Tan(θ) distortion curve of the optical lens provided in Example 1 of the present invention.

[0030] Figure 5 This is an MTF curve diagram of the optical lens provided in Example 1 of the present invention.

[0031] Figure 6 Schematic diagram of the structure of the optical lens provided in Example 2 of the present invention.

[0032] Figure 7 This is a field curvature curve diagram of the optical lens provided in Example 2 of the present invention.

[0033] Figure 8 This is a F-Tan(θ) distortion curve of the optical lens provided in Example 2 of the present invention.

[0034] Fig. 9 This is an MTF curve diagram of the optical lens provided in Example 2 of the present invention.

[0035] Fig.10 Schematic diagram of the structure of the optical lens provided in Example 3 of the present invention.

[0036] Fig.11 This is a field curvature curve diagram of the optical lens provided in Example 3 of the present invention.

[0037] Fig.12 This is a F-Tan(θ) distortion curve diagram of the optical lens provided in Example 3 of the present invention.

[0038] Fig.13 This is an MTF curve diagram of the optical lens provided in Example 3 of the present invention.

[0039] Fig.14 This is a schematic diagram of the optical path of the near-eye display device provided in Example 4 of the present invention.

[0040] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0041] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of the embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0042] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0043] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0044] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the convex position is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at least in the paraxial region.

[0045] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", when used in this specification, indicate the presence of the stated features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0046] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0047] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0048] The present invention provides an optical lens, which is used to modulate the light signal emitted by the image source and transmit it to the entrance pupil side of the human eye. The optical lens is arranged in the light emitting direction of the image source, that is, the emitting surface of the image source is the light emitting side of the light signal. The optical lens is composed of five lenses, and includes: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens in sequence from the entrance pupil side of the human eye to the image source side along the opposite direction of light transmission. The first lens, the second lens, the third lens, the fourth lens, and the fifth lens each include a light entrance surface close to the image source side and a light exit surface close to the entrance pupil side of the human eye. It can be understood that the surface of each lens close to the image source is called the light entrance surface of the lens, and the surface of each lens close to the entrance pupil side of the human eye is called the light exit surface of the lens. It should be noted that the entrance pupil position of the human eye is the aperture of the optical lens.

[0049] In some embodiments, the first lens may have positive focal power, the light exiting surface of the first lens is convex, and the light incident surface of the first lens is concave or convex. The second lens may have positive focal power or negative focal power, the light exiting surface of the second lens is convex, and the light incident surface of the second lens is concave or convex. The third lens may have negative focal power, the light exiting surface of the third lens is concave, and the light incident surface of the third lens is concave. The fourth lens may have positive focal power, the light exiting surface of the fourth lens is concave or convex, and the light incident surface of the fourth lens is convex. The fifth lens has positive focal power, the light exiting surface of the fifth lens is concave or convex, and the light incident surface of the fifth lens is concave or convex.

[0050] In order to meet the wearing needs of users with different refractive degrees, the air spacing CT between the entire lens group (composed of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens) and the image source on the optical axis can be dynamically adjusted. W (i.e., the distance between the light incident surface of the fifth lens and the image source on the optical axis) to achieve the adjustment of the optical lens between different refractive powers, so as to well meet the wearing needs of users with different refractive powers. More specifically, the distance CT between the light incident surface of the fifth lens and the image source side on the optical axis is W The adjustment range meets: 3.3mm <CT W <48mm. Meeting the above conditions can make the lens have a larger optical back focus. On the one hand, it can make the light emitted from the image source side have a larger refraction space, improve the adaptability of the optical lens to the large-size display screen, and at the same time reserve a larger space between the image source and the optical lens to facilitate the adjustment of the distance between the two, so as to achieve a larger range (such as -7D to +3D) of diopter adjustment, which can meet the wearing needs of users with different myopia or hyperopia. And the diopter adjustment method of this application is simple, which can be achieved by moving the screen.

[0051] In some embodiments, the distance TL on the optical axis from the light-emitting surface of the first lens to the light-incident surface of the fifth lens and the effective focal length f of the optical lens satisfy: 0.9 < TL / f < 1.1; the distance TL on the optical axis from the light-emitting surface of the first lens to the light-incident surface of the fifth lens and the display area length IH of the image source that the optical lens can match satisfy: 1.9 < TL / IH < 2.2. Meeting the above conditions can make the lens have a longer focal length, be able to better present larger local details, improve the picture quality, and at the same time make the lens have a larger image plane, be able to match a larger-sized image source (display screen) to achieve high-definition imaging, and bring an excellent sensory experience to the user.

[0052] In some embodiments, the display area length IH of the image source that the optical lens can match and the effective focal length f of the optical lens satisfy: 0.48 < IH / f < 0.5. Meeting the above conditions can enable the optical lens to match a larger-sized image source (display screen) to achieve high-definition imaging, bring an excellent sensory experience to the user, and at the same time be beneficial to realizing the telephoto performance of the lens, be able to better present larger local details, make the picture more concentrated and compact, so as to meet the visual experience of the human eye. Preferably, the display area length IH of the image source that the optical lens can match and the effective focal length f of the optical lens satisfy: 0.49 < IH / f < 0.5.

[0053] In some embodiments, the exit pupil distance ED of the optical lens and the effective focal length f of the optical lens satisfy: 0.29 < ED / f < 0.3. The exit pupil distance ED represents the distance on the optical axis from the entrance pupil side of the human eye to the light-emitting surface of the first lens. Meeting the above conditions can make the lens have a larger entrance pupil distance, reduce the dizziness when the human eye wears it, and improve the sensory experience.

[0054] In some embodiments, the effective focal length f of the optical lens and the combined focal length f345 of the third, fourth, and fifth lenses satisfy: 0.4 < f345 / f < 2.5. Meeting the above conditions is beneficial for the light rays emitted from the image source side to smoothly transition to the human eye observation area, and at the same time is beneficial for correcting various aberrations of the optical lens and improving the imaging quality of the optical lens. Preferably, the effective focal length f of the optical lens and the combined focal length f345 of the third, fourth, and fifth lenses satisfy: 0.5 < f345 / f < 2.3.

[0055] In some embodiments, the effective aperture DM11 of the light-emitting surface of the first lens and the effective aperture DM52 of the light-incident surface of the fifth lens satisfy: 0.38 < DM11 / DM52 < 0.44; the maximum effective aperture DM1 of the first lens, the maximum effective aperture DM2 of the second lens, the maximum effective aperture DM3 of the third lens, the maximum effective aperture DM4 of the fourth lens, and the maximum effective aperture DM5 of the fifth lens satisfy: DM1 < DM2 < DM3 < DM4 < DM5. Meeting the above conditions, by reasonably setting the aperture relationship of each lens, the light emitted by the display screen can enter the human eye observation area at a relatively parallel and wide viewing angle, while ensuring a large eye movement range of the system and improving the user experience comfort. Preferably, the effective aperture DM11 of the light-emitting surface of the first lens and the effective aperture DM52 of the light-incident surface of the fifth lens satisfy: 0.4 < DM11 / DM52 < 0.43.

[0056] In some embodiments, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.5 < f1 / f < 4. Meeting the above conditions can effectively converge the light, so that the outgoing light enters the human eye observation area at a relatively parallel viewing angle, providing a better immersive experience for the user. Preferably, the effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.6 < f1 / f < 3.8.

[0057] In some embodiments, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -1.2 < f3 / f < -0.2; the effective focal length f of the optical lens and the radius of curvature R6 of the light-incident surface of the third lens satisfy: 0.1 < R6 / f < 1. Meeting the above conditions can greatly diverge the light emitted from the image source side to increase the area of the projected virtual image, providing a better immersive experience for the user. Preferably, the effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -1.1 < f3 / f < -0.3; the effective focal length f of the optical lens and the radius of curvature R6 of the light-incident surface of the third lens satisfy: 0.2 < R6 / f < 0.9.

[0058] In some embodiments, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.3 < f4 / f < 6.5; the effective focal length f of the optical lens and the radius of curvature R8 of the light-incident surface of the fourth lens satisfy: -4 < R8 / f < -0.4. Meeting the above conditions is beneficial to the further convergence of the light, enabling the light emitted from the image source side to smoothly enter the rear optical system, reducing the correction difficulty of various aberrations, and better realizing the high-quality imaging of the lens. Preferably, the effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.4 < f4 / f < 6; the effective focal length f of the optical lens and the radius of curvature R8 of the light-incident surface of the fourth lens satisfy: -3.9 < R8 / f < -0.5.

[0059] In some embodiments, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.5 < f5 / f < 1.6. Meeting the above conditions is beneficial to converging the light rays emitted from the image source side and reducing the divergence degree of the light rays, so as to enter the human eye at a nearly parallel viewing angle, ensuring a large field of view while improving the overall imaging quality. Preferably, the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.6 < f5 / f < 1.5.

[0060] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the fifth lens along the optical axis respectively and the distance TL on the optical axis from the light-emitting surface of the first lens to the light-incident surface of the fifth lens satisfy: 0.5 < ∑CT / TL < 0.7. Meeting the above conditions can make the structure of the lens more compact, and at the same time facilitate the movement of the image source (display degree) for diopter adjustment, so as to meet the wearing needs of users with different diopters.

[0061] In some embodiments, the central thickness CT1 of the first lens and the air gap CT12 between the first lens and the second lens on the optical axis satisfy: 0.2 < CT1 / CT12 < 0.8; the central thickness CT2 of the second lens and the air gap CT12 between the first lens and the second lens on the optical axis satisfy: 0.35 < CT2 / CT12 < 0.6. Meeting the above conditions, by reasonably controlling the ratio of the central thicknesses and the air intervals of the first and second lenses, the distribution of light rays can be effectively adjusted, the sensitivity of the optical lens can be reduced, and at the same time it is beneficial to the processing and assembly of the lens, improving the production yield.

[0062] In some embodiments, the sum ∑CT of the central thicknesses of the first lens to the fifth lens along the optical axis respectively and the sum ∑AT of the distances between any two adjacent lenses of the first lens to the fifth lens on the optical axis satisfy: 1.1 < ∑CT / ∑AT < 2. Meeting the above conditions can make the structure of the lens more compact and is beneficial to realizing the miniaturization of the lens.

[0063] In some embodiments, the optical lens satisfies the conditional formula: 80 mm < TTL < 87 mm; 48 mm < f < 53 mm; 25° < FOV < 30°; 23 mm < IH < 28 mm; where TTL represents the overall optical length of the optical lens, f represents the effective focal length of the optical lens, FOV represents the maximum field of view angle of the optical lens, and IH represents the length of the display area of the image source that the optical lens can match. Meeting the above conditions indicates that the optical lens provided by the embodiments of the present invention has the advantages of long focal length characteristics and being able to match a 4K high-resolution screen to achieve high-definition imaging.

[0064] In some embodiments, the lens material in the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. When the lens material is glass, the geometric chromatic aberration of the optical lens can be effectively corrected by the low dispersion characteristic of the glass itself. The first lens, the second lens, the third lens, the fourth lens, and the fifth lens are all plastic lenses.

[0065] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens may be spherical lenses or aspherical lenses. Compared with spherical structures, aspherical structures can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and reducing the size of lenses, and better realizing miniaturization of lenses. More specifically, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens of the present invention may all be aspherical lenses, which can effectively reduce the aberration of the optical lens, thereby reducing the number of lenses and reducing the size of lenses, and better realizing miniaturization of lenses.

[0066] In various embodiments of the present invention, when the lens is an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations:

[0067] ;

[0068] Among them, z is the distance between the surface and the vertex of the surface in the direction of the optical axis, h is the distance from the optical axis to the surface, c is the curvature of the surface vertex, K is the quadratic surface coefficient, B, C, D, E, F, G, and H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients respectively.

[0069] In addition, the present invention also provides a near-eye display device, which includes, in sequence along the direction of light signal transmission: an image source, the above-mentioned optical lens; the image source is used to emit a light signal, and the light signal includes image information; the optical lens is arranged in the light emitting direction of the image source, and the fifth lens is arranged closer to the image source than the first lens, and the optical lens is used to modulate the light signal emitted by the image source and transmit it to the human eye.

[0070] The present invention is further described below in multiple embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different. For specific differences, please refer to the parameter table of each embodiment. The following embodiments are only preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any other changes, substitutions, combinations or simplifications that do not deviate from the innovative points of the present invention should be regarded as equivalent replacement methods and are included in the protection scope of the present invention.

[0071] Example 1

[0072] See also Figure 1 , which is a schematic diagram of the structure of a near-eye display device 400 provided in an embodiment of the present invention, please refer to Figure 2 , which is a schematic diagram of the structure of the optical lens 100 provided in Embodiment 1 of the present invention, is used to modulate the optical signal emitted by the image source 10 and transmit it to the entrance pupil side of the human eye. The optical lens 100 is arranged in the light emitting direction of the image source 10, that is, the emitting surface of the image source 10 is the light emitting side of the optical signal. Figure 2 It can be seen that the optical lens 100 is sequentially provided with the following components along the opposite direction of light transmission (i.e., from the entrance pupil side of the human eye to the image source side): an aperture ST, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5. The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 each include a light entrance surface close to the image source side and a light exit surface close to the entrance pupil side of the human eye. It can be understood that the surface of each lens close to the image source 10 is called the light entrance surface of the lens, and the surface of each lens close to the entrance pupil side of the human eye is called the light exit surface of the lens. It should be noted that the entrance pupil position of the human eye is the aperture ST of the optical lens 100.

[0073] The first lens L1 has positive refractive power, a light exiting surface S1 of the first lens is a convex surface, and a light incident surface S2 of the first lens is a concave surface;

[0074] The second lens L2 has negative optical power, a light exiting surface S3 of the second lens is a convex surface, and a light incident surface S4 of the second lens is a concave surface;

[0075] The third lens L3 has negative optical power, a light exiting surface S5 of the third lens is a concave surface, and a light incident surface S6 of the third lens is a concave surface;

[0076] The fourth lens L4 has positive refractive power, a light exiting surface S7 of the fourth lens is a convex surface, and a light incident surface S8 of the fourth lens is a convex surface;

[0077] The fifth lens L5 has positive refractive power, a light-exiting surface S9 of the fifth lens L5 is a concave surface, and a light-incident surface S10 of the fifth lens L5 is a convex surface.

[0078] The first lens L1, the second lens L2, the third lens L3, the fourth lens L4 and the fifth lens L5 are all plastic aspherical lenses.

[0079] In order to meet the wearing needs of users with different refractive degrees, the air spacing CT between the entire lens group (composed of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5) and the image source 10 on the optical axis can be dynamically adjusted. W(The distance between the light incident surface of the fifth lens L5 and the image source 10 on the optical axis) is used to realize the adjustment of the optical lens between different refractive powers, thereby being able to well meet the wearing needs of users with different refractive powers.

[0080] Specifically, in this embodiment, the distance CT between the light incident surface of the fifth lens and the image source side on the optical axis is W The adjustment range is 20.514~46.663mm, which can achieve -700~300 degrees (-7D~3D) of diopter adjustment, so that users with different degrees of myopia or hyperopia can have a good sensory experience when wearing it. Figure 2 , which is a schematic diagram of the structure of the optical lens 100 when the diopter is 0D (0°). W is 37.123mm; when CT W When the CT W When the angle of the optical lens 100 is 46.663 mm, the diopter of the optical lens 100 is 3D (300°). In this embodiment, the diopter can be adjusted by moving the display screen.

[0081] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0082] Table 1-1

[0083]

[0084] The surface parameters of the aspheric lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0085] Table 1-2

[0086]

[0087] Please refer to Figure 3 , which is a field curvature curve of the optical lens 100, indicating the degree of curvature of light on the meridional image plane and the sagittal image plane, the horizontal axis indicates the offset (unit: mm), and the vertical axis indicates the field angle (unit: °). It can be seen from the figure that the field curvature of the meridional image plane and the sagittal image plane is controlled within ±0.3mm, indicating that the optical lens 100 can correct the field curvature well.

[0088] Please refer to Figure 4 , which is a F-Tan(θ) distortion curve of the optical lens 100, wherein the horizontal axis represents the F-Tan(θ) distortion percentage, and the vertical axis represents the field of view angle (unit: degree). Figure 4 It can be seen that the F-Tan (θ) distortion value at the image height received by the user's eyes is controlled within ±1.6%, indicating that the distortion of the optical lens 100 is well corrected.

[0089] Please refer to Figure 5 , which is a graph of the MTF (Modulation Transfer Function) of the optical lens 100, which indicates the imaging modulation of the lens at different spatial frequencies under each field of view, the horizontal axis indicates the spatial frequency (unit: lp / mm), and the vertical axis indicates the MTF value. It can be seen from the figure that the MTF value of the present embodiment is above 0.7 in the entire field of view, and the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0090] from Figure 3 , Figure 4 , Figure 5 It can be seen that the aberration of the optical lens 100 is well balanced and has good imaging quality.

[0091] Example 2

[0092] See also Figure 6 , shown is a schematic diagram of the structure of the optical lens 200 provided in Example 2 of the present invention. Compared with Example 1, the main differences of this embodiment are: the second lens L2 has positive focal power; the light incident surface S2 of the first lens L1 is a convex surface; the light exit surface S9 of the fifth lens L5 is a convex surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0093] In this embodiment, the distance CT between the light incident surface of the fifth lens and the image source side on the optical axis is W The adjustment range is 14.212~40.378mm. Figure 6 , which is a schematic diagram of the structure of the optical lens 200 when the diopter is 0D (0°). W is 30.792mm; when CT W When the CT W When the diameter of the optical lens 200 is 40.378 mm, the refractive power of the optical lens 200 is 3D (300°).

[0094] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0095] Table 2-1

[0096]

[0097] The surface parameters of the aspheric lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0098] Table 2-2

[0099]

[0100] Please refer to Figure 7 , which is a field curvature curve of the optical lens 200, indicating the degree of curvature of light in the meridian image plane and the sagittal image plane, the horizontal axis indicates the offset (unit: mm), and the vertical axis indicates the field angle (unit: °). It can be seen from the figure that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.3mm, indicating that the optical lens 200 can correct the field curvature well.

[0101] Please refer to Figure 8 , which is a F-Tan(θ) distortion curve of the optical lens 200, wherein the horizontal axis represents the F-Tan(θ) distortion percentage, and the vertical axis represents the field of view angle (unit: degree). Figure 8 It can be seen that the F-Tan (θ) distortion value at the image height received by the user's eyes is controlled within ±1.6%, indicating that the distortion of the optical lens 200 is well corrected.

[0102] Please refer to Fig. 9 , which is a graph of the MTF (Modulation Transfer Function) of the optical lens 200, indicating the imaging modulation of the lens at different spatial frequencies under each field of view, the horizontal axis indicates the spatial frequency (unit: lp / mm), and the vertical axis indicates the MTF value. It can be seen from the figure that the MTF value of the present embodiment is above 0.7 in the entire field of view, and the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution capability in both low-frequency and high-frequency conditions.

[0103] from Figure 7 , Figure 8 , Fig. 9 It can be seen that the aberration of the optical lens 200 is well balanced and has good imaging quality.

[0104] Example 3

[0105] See also Fig.10 , shown is a schematic diagram of the structure of the optical lens 300 provided in Example 3 of the present invention. Compared with Example 1, the main differences of this embodiment are: the second lens L2 has positive focal power; the light incident surface S2 of the first lens L1 is a convex surface; the light incident surface S4 of the second lens L2 is a convex surface; the light emitting surface S7 of the fourth lens L4 is a concave surface; the light emitting surface S9 of the fifth lens L5 is a convex surface; the light incident surface S10 of the fifth lens L5 is a concave surface; the optical parameters such as the curvature radius of each lens surface and the lens thickness are different.

[0106] In this embodiment, the distance CT between the light incident surface of the fifth lens and the image source side on the optical axis is W The adjustment range is 3.667~29.79mm. Fig.10, which is a schematic diagram of the structure of the optical lens 300 when the diopter is 0D (0°). W is 20.279mm; when CT W When the CT W When the diameter of the optical lens 300 is 29.79 mm, the refractive power of the optical lens 300 is 3D (300°).

[0107] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0108] Table 3-1

[0109]

[0110] The surface parameters of the aspheric lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0111] Table 3-2

[0112]

[0113] Please refer to Fig.11 , which is a field curvature curve of the optical lens 300, indicating the degree of curvature of light in the meridian image plane and the sagittal image plane, the horizontal axis indicates the offset (unit: mm), and the vertical axis indicates the field angle (unit: °). It can be seen from the figure that the field curvature of the meridian image plane and the sagittal image plane is controlled within ±0.4mm, indicating that the optical lens 300 can correct the field curvature well.

[0114] Please refer to Fig.12 , which is a F-Tan(θ) distortion curve of the optical lens 300, wherein the horizontal axis represents the F-Tan(θ) distortion percentage, and the vertical axis represents the field of view angle (unit: degree). Fig.12 It can be seen that the F-Tan (θ) distortion value at the image height received by the user's eyes is controlled within ±1.2%, indicating that the distortion of the optical lens 300 is well corrected.

[0115] Please refer to Fig.13 , which is a graph of the MTF (modulation transfer function) of the optical lens 300, indicating the imaging modulation degree of the lens at different spatial frequencies under each field of view, the horizontal axis indicates the spatial frequency (unit: lp / mm), and the vertical axis indicates the MTF value. It can be seen from the figure that the MTF value of the present embodiment is above 0.7 in the whole field of view, and the MTF curve decreases evenly and smoothly from the center to the edge of the field of view, and has good imaging quality and good detail resolution ability in both low-frequency and high-frequency conditions.

[0116] from Fig.11 , Fig.12 , Fig.13 It can be seen that the aberration of the optical lens 300 is well balanced and has good imaging quality.

[0117] Please refer to Table 4, which shows the optical characteristics of the optical lenses provided by the above three embodiments when the diopter is 0D (0°), including the effective focal length f of the optical lens, the total optical length TTL, the distance TL on the optical axis from the light exit surface of the first lens to the light entrance surface of the fifth lens, the aperture value Fno, the maximum field of view FOV, the entrance pupil diameter EPD, the exit pupil distance ED, and the display area length IH of the image source that the optical lens can match, and the numerical value corresponding to each conditional expression in each embodiment.

[0118] Table 4

[0119]

[0120] In summary, the optical lens provided by the present invention has at least the following advantages:

[0121] (1) Through specific surface shape settings and reasonable optical focal length distribution, the optical lens has a telephoto characteristic, which can better present larger local details and improve image quality. At the same time, the optical lens has the characteristics of low distortion, which improves the imaging quality and brings a better experience to users.

[0122] (2) The optical lens also has a larger image surface and higher resolution, which can match a larger image source (display screen) to achieve high-definition imaging, bringing users an excellent sensory experience.

[0123] (3) Different diopter adjustments can be achieved by adjusting the spatial distance between the lens group and the image source on the optical axis. A wide range of diopter adjustments (-7D to +3D) can be achieved, and all have high imaging quality, which can meet the needs of different myopic users. At the same time, it has a larger exit pupil distance, which can provide users with a better experience.

[0124] Example 4

[0125] See also Fig.14 , which is a schematic diagram of an optical path in a near-eye display device 400 provided in an embodiment of the present invention, the near-eye display device 400 includes an image source 10, an optical lens (such as optical lens 100) in any of the aforementioned embodiments of the present application, and the optical lens 100 is located between the human eye 20 and the image source 10. The image information emitted from the image source 10 enters the human eye 20 through the optical lens 100 to form an image, and a high-definition magnified virtual image can be observed in the human eye 20, which has an extremely realistic sensory experience.

[0126] The image source 10 is used to emit a light signal, and the light signal includes image information. Specifically, the image source 10 can be one of a display screen such as Micro LED, OLED, LCD, LCOS, M-OLED, etc., and can provide high-definition image information for the optical lens 100.

[0127] The optical lens 100 is arranged in the light emitting direction of the image source 10 , and the fifth lens in the optical lens 100 is arranged closer to the image source 10 than the first lens. The optical lens 100 is used to modulate the light signal emitted by the image source 10 and transmit it to the human eye 20 .

[0128] The near-eye display device 400 can be VR glasses, VR helmets, head-mounted display devices, etc. By adjusting the distance between the lens and the image source side, the diopter can be adjusted (-7D~3D), so that users with different degrees of myopia or hyperopia can have a better wearing experience. Since the above-mentioned optical lens has a telephoto characteristic and the optical lens has the characteristics of low distortion, the imaging quality is improved, which brings a better experience to the user. At the same time, the optical lens also has a larger image surface and a higher resolution. The light signal image modulated by the optical lens is bright and clear, the effect is better, and the picture projected to the human eye is clearer. Therefore, the near-eye display device equipped with the optical lens has at least the characteristics of small distortion and high image quality, which can effectively improve the user's visual experience and comfort.

[0129] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0130] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An optical lens, consisting of five lenses, characterized in that: Along the reverse direction of light transmission, from the side of the entrance pupil of the human eye to the side of the image source, it successively includes: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens; each of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens includes an incident light surface close to the side of the image source and an emergent light surface close to the side of the entrance pupil of the human eye; The first lens has a positive optical power, and the emergent light surface of the first lens is a convex surface; The second lens has an optical power, and the emergent light surface of the second lens is a convex surface; The third lens has a negative optical power, the emergent light surface of the third lens is a concave surface, and the incident light surface of the third lens is a concave surface; The fourth lens has a positive optical power, and the incident light surface of the fourth lens is a convex surface; The fifth lens has a positive optical power; The distance CT between the light incident surface of the fifth lens and the image source on the optical axis W The range is adjustable; Wherein, the distance TL on the optical axis from the emergent light surface of the first lens to the incident light surface of the fifth lens and the effective focal length f of the optical lens satisfy: 0.9 < TL / f < 1.1; The distance TL on the optical axis from the emergent light surface of the first lens to the incident light surface of the fifth lens and the display area length IH of the image source that the optical lens can match satisfy: 1.9 < TL / IH < 2.2; the effective focal length f of the optical lens and the focal length f5 of the fifth lens satisfy: 0.5 < f5 / f < 1.

6.

2. The optical lens according to claim 1, characterized in that: The display area length IH of the image source that the optical lens can match and the effective focal length f of the optical lens satisfy: 0.48 < IH / f < 0.5; the exit pupil distance ED of the optical lens and the effective focal length f of the optical lens satisfy: 0.29 < ED / f < 0.

3.

3. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the combined focal length f345 of the third lens, the fourth lens, and the fifth lens satisfy: 0.4 < f345 / f < 2.

5.

4. The optical lens according to claim 1, characterized in that: The effective aperture DM11 of the emergent light surface of the first lens and the effective aperture DM52 of the incident light surface of the fifth lens satisfy: 0.38 < DM11 / DM52 < 0.44; the maximum effective aperture DM1 of the first lens, the maximum effective aperture DM2 of the second lens, the maximum effective aperture DM3 of the third lens, the maximum effective aperture DM4 of the fourth lens, and the maximum effective aperture DM5 of the fifth lens satisfy: DM1 < DM2 < DM3 < DM4 < DM5.

5. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f1 of the first lens satisfy: 1.5 < f1 / f < 4.

6. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f3 of the third lens satisfy: -1.2 < f3 / f < -0.2; the effective focal length f of the optical lens and the radius of curvature R6 of the incident light surface of the third lens satisfy: 0.1 < R6 / f < 1.

7. The optical lens according to claim 1, characterized in that: The effective focal length f of the optical lens and the focal length f4 of the fourth lens satisfy: 0.3 < f4 / f < 6.5; the effective focal length f of the optical lens and the radius of curvature R8 of the incident light surface of the fourth lens satisfy: -4 < R8 / f < -0.

4.

8. The optical lens according to claim 1, characterized in that: The sum ∑CT of the central thicknesses of the first lens to the fifth lens along the optical axis respectively and the distance TL on the optical axis from the light-emitting surface of the first lens to the light-incident surface of the fifth lens satisfy: 0.5 < ∑CT / TL < 0.

7.

9. The optical lens according to claim 1, characterized in that: The central thickness CT1 of the first lens and the air gap CT12 between the first lens and the second lens on the optical axis satisfy: 0.2 < CT1 / CT12 < 0.8; the central thickness CT2 of the second lens and the air gap CT12 between the first lens and the second lens on the optical axis satisfy: 0.35 < CT2 / CT12 < 0.

6.

10. A near-eye display device, characterized in that: It sequentially includes, along the optical signal transmission direction: an image source, and an optical lens as described in any one of claims 1-9; The image source is configured to emit an optical signal, and the optical signal includes image information; The optical lens is disposed in the light-emitting direction of the image source, and the fifth lens is disposed closer to the image source than the first lens, and the optical lens is configured to modulate the optical signal emitted by the image source and transmit it to the human eye.

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